Parquet does not support reflected records

I just noticed while looking in the parquet code that it's avro support doesn't work for reflected records, just specific and generic (see AvroIndexedRecordConverter line 125). I think this is probably because the reflect setter methods aren't easily available outside of the ReflectData family (I tried to use it for CSV support). Adding support would probably require some changes to Avro to make reusing that code more clean.